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我有一个启用了分页的 UIScrollView，页面上有多个子视图：UIButton、UIwebview 和 UIImageView。每个页面上的 webview 和图像都会发生变化。这工作正常。我使用 Apples滚动图像分页示例来帮助我入门。

但是当我添加第二个 UIImageView 时，我所在的图像位置已经获得了新值，并且新图像不会显示。

这是第一张图片的 viewdidload 内的代码（工作正常）：

// load all the images from our bundle and add them to the scroll view
for (i = 1; i <= kNumImages; i++)
{
    NSString *imageName = [NSString stringWithFormat:@"image%d.jpg", i];
    UIImage *image2 = [UIImage imageNamed:imageName];
    UIImageView *imageView2 = [[UIImageView alloc] initWithImage:image2];


    // setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
    CGRect rect = imageView2.frame;
    rect.size.height = imageviewScrollObjHeight;
    rect.size.width = imageviewScrollObjWidth;

    // Get the Layer of any view
    CALayer * imageLayer = [imageView2 layer];
    [imageLayer setMasksToBounds:YES];
    [imageLayer setCornerRadius:7.0];

    // You can even add a border
    [imageLayer setBorderWidth:1.0];
    [imageLayer setBorderColor:[[UIColor lightGrayColor] CGColor]];

    imageView2.frame = rect;
    imageView2.tag = i; // tag our images for later use when we place them in serial fashion  


    [scrollView1 addSubview:imageView2];

}

[self layoutScrollImages];  // now place the photos in serial layout within the scrollview

这是在每个页面上布局第一个图像的代码，每页不同的图像（外部 viewdidload）（工作正常）：

// layout images for imageview1
- (void)layoutScrollImages
{
UIImageView *imageView = nil;
NSArray *subviews = [scrollView1 subviews];

// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 10;
for (imageView in subviews)
{
    if ([imageView isKindOfClass:[UIImageView class]] && imageView.tag > 0)
    {
        CGRect frame = imageView.frame;
        frame.origin = CGPointMake(curXLoc, 50);
        imageView.frame = frame;

        curXLoc += (kScrollObjWidth);
    }
}

// set the content size so it can be scrollable
[scrollView1 setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [scrollView1 bounds].size.height)];
}

这是第二张图片的代码（在 viewdidload 内）：（当我删除 [self layoutNavScrollImages] 时；图片仅在第一页上加载）

for (i = 1; i <= kNumImages; i++)
{

    UIImage *navBarImage = [UIImage imageNamed:@"navigationbar.png"];
    UIImageView *imageViewNavBar = [[UIImageView alloc] initWithImage:navBarImage];

    // setup each frame to a default height and width, it will be properly placed when we call "updateScrollList"
    CGRect navBarRect = imageViewNavBar.frame;
    navBarRect.size.height = 44;
    navBarRect.size.width = 320;
    navBarRect.origin.x = 0;
    navBarRect.origin.y = 0;

    /* Get the Layer of any view
     CALayer * imageLayer = [imageView3 layer];
     [imageLayer setMasksToBounds:YES];
     [imageLayer setCornerRadius:7.0];

     // You can even add a border
     [imageLayer setBorderWidth:1.0];
     [imageLayer setBorderColor:[[UIColor lightGrayColor] CGColor]];
     */
    imageViewNavBar.frame = navBarRect;
    imageViewNavBar.tag = i;    // tag our images for later use when we place them in serial fashion  

    [scrollView1 addSubview:imageViewNavBar];

}

[self layoutNavScrollImages];

以及viewdidload之外的代码：（这会覆盖第一张图片的位置）

- (void)layoutNavScrollImages
{
UIImageView *view = nil;
NSArray *subviews = [scrollView1 subviews];

// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 0;
for (view in subviews)
{
    if ([view isKindOfClass:[UIImageView class]] && view.tag > 0)
    {
        CGRect frame = view.frame;
        frame.origin = CGPointMake(curXLoc, 0);
        view.frame = frame;

        curXLoc += (kScrollObjWidth);
    }
}

// set the content size so it can be scrollable
[scrollView1 setContentSize:CGSizeMake((kNumImages * kScrollObjWidth), [scrollView1 bounds].size.height)];
}
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1 回答 1

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这样做的方法是制作一个（大）UIView 并将每个 UIImageView 添加为该 UIView 的子视图。然后将 UIView 作为子视图添加到 UIScrollView。

[totalView addSubview:imageView1];
[totalView addSubview:imageView2;
[totalView addSubview:buttonView1];
[totalView addSubview:buttonView2];
[totalView addSubview:webView];

[scrollView addSubview:totalView];

请务必设置正确的内容大小，否则滚动视图将不起作用：

[scrollView setContentSize:CGSizeMake((320*kNumImages), 411)];

设置视图并标记 UIView（在 viewdidload 内）：

NSUInteger i;
for (i = 1; i <= kNumImages; i++)
   {
      //... code to setup views
      totalView.tag = i;
   }
[self layoutViews]; // now place the views in serial layout within the scrollview

然后在每个页面上布局视图：

- (void)layoutViews
{
UIView *view = nil;
NSArray *subviews = [scrollView subviews];

// reposition all image subviews in a horizontal serial fashion
CGFloat curXLoc = 0;
for (view in subviews)
{
    if ([view isKindOfClass:[UIView class]] && view.tag > 0)
    {
        CGRect frame = view.frame;
        frame.origin = CGPointMake(curXLoc, 0);
        view.frame = frame;

        curXLoc += (kScrollObjWidth);
    }
}
}

我希望这尽可能清楚。如果有人认为这不是正确的做法，请发表评论。

于 2012-06-01T12:34:47.373 回答